Gramophone and like machine



March 10, 1925.

s. w. J. MACPHERSON GRAMOPHONE AND LIKE MACHINE Filed March 8, 1924 mvemon J a Ml'anJW/kva'om Patented Mar. 10, 1925.,

UNITED STATES PATENT OFFICE.

, GRAMOPHONE AND LIKE MACHINE.

Applicationfiled March a, 1924. Serial No. 697,709.

ToaZZ whom z'tmay. concern:

Be it known that I, SYDNEY W'ILLIAM JAMEs MACPHERSON, of 14; Alma Road, Sheernesson-Sea, in the county of Kent,

England, a British subject, have invented certain new and useful Improvements in or Relating to Gramophones and like Machines,

of which the following is a specification.

This invention relates to gramophones or like machines (hereinafter referred to as gramophones) adapted for recording or reproducing a rendition on or from a disc record whereon the linear movement of the undulating track under the stylus required for recording or reproduction during a given unit of time is substantially the same throughout the entire length of said undulating track, constant linear velocity of said track under the stylus being brought about by controlling the speed regulating mechanism of the gramophone by means attached to an arm or lever attached to the tone arm of the machine.

The object of the invention is to provide improved means for controlling automatically the angular velocity of the disc record so as to obtain the aforesaid constant linear velocity of the record track under the stylus and also to provide such means which may be attached readily to an existing machine and which may be brought into use or disconnected, with great facility by an unskilled operator.

According to this invention the automatic control of the angular velocity of a disc record is effected by connecting the handle of the speed regulating lever with the tone arm so that as the latter moves towards (or away from) the centre of the revolving record said handle is moved in consonance therewith and the speed is regulated to correspond with the radial distance of the needle or other stylus from the centre of the record.

1 The desired connection may be established by a clip or like fitting adapted to be secured on the tone arm and a link pivoted thereto and formed with an eye adapted to be fitted over the handle of the speed regulating lever. Alternatively the link may be pivoted to a lug integral with the tone arm.

Two forms of the invention are shown,

by way of example, in the accompanying drawings, of which Figural ,is a planJof the record table, tone arm and control portion of the speed regulating mechanism of a gramophone, parts being broken away and parts being omitted for the sake of clearness, and Figure 2 is a similar view of part of a tone arm illustrating a modified detail.

As shown in Figure 1 a clip a surrounds and is secured to the tone'arm b of a gramophone by a screw 0 which serves also as a pivot pin for an eye in one end of a link (Z the other end of which is also formed with an eye adapted to be slipped over the upstanding handle 0 of the lever f of the control portion of the speed regulating mechanism (not shown) for the record table 5 The control portion of the speed regulating mechanism, which does not form any part of this invention comprises the lever f pivoted at h and adapted to be clamped by a screw to a plate formed with a cam slot m coacting with an arm n projecting thereinto from the speed regulating mechanism. When the eye on the free end of the link (Z is slipped over the handle c, a record formed as above set forth is placed on the record table 9' and the latter is caused to revolve with the needle 0 in the record groove. The angular movement of the tone arm Z) due to the spiral formation of the record groove, is transmitted through the link (Z to the lever f with the result that the angular velocity of the record is controlled to correspond with the radial distance of the needle 0 from the centre of the record. I

When a record of ordinary type is to be used the link (Z is disconnected from the lever f and the latter is set in the usual manner. If desired the connection of the link cl with the clip a may be such that it may be readily detachable therefrom instead of, or as well as, from the handle '0, whilst instead of a clip a, a lug such as p, Figure 2 may be formed integrally on the tone arm 6.

It is of course desirable that the clip a should be secured on, or the lug 22 formed on, the tone arm 6 at such a distance from the axis of rotation of said tone arm, as to produce a variation of the angular velocity of the table 9 within a predetermined range.

As will be understood the change necessary for playing the one or the other kind of record can be effected by an. unskilled a link pivoted to said clip, said link being 15 operator Whilst the additional cost of the adjunct is practically negligible.

I claim 2-- l. A talking machine having a movable tone arm and a speed regulating lever with a handle thereon, a link pivoted to said tone arm, said link being formed with an eye adapted to be slipped over said handle, and the movement of said tone armthus transmitted to said lever.

2. A talking machine having a movable tone arm, and a speed regulating lever with a handle thereon, a clip on said tone arm,

formed with an eye adapted to he slipped over said handle, and the movement of said tone arm thus transmitted to said lever.

'3. An attachment, for use on a talking machine having a movable tone arm and a speed regulating lever with a handle thereon, comprising a clip adapted to be fitted on said tone arm and a link pivoted to said clip, said link being formed with an eye adapted to be slipped over said handle, substantially as set forth.

SYDNEY WILLIAM JAMES MACPHERSON. 

